The present invention relates to capacitive touch sensors and more particularly to a method and apparatus to produce electric and magnetic fields to emulate single touch, multiple touch and touch gestures on a capacitive touch sensors providing improved accuracy, sensitivity and enhanced capabilities.
Capacitive touch sensor technology has been integrated into many products and enables capacitive touch pads and capacitive touch screens to sense finger location and finger gesture movement. In addition, capacitive touch sensor technology can also sense and track multiple finger movement gestures commonly referred to as multi-touch. Furthermore, capacitive switches can also detect touch events. Many passive devices such as capacitive styluses have been created for use with capacitive touch sense technology which emulate a finger touch and allow users to perform hand writing in addition to other functions including joystick controllers. Heretofore, passive devices function by capacitively coupling to nearby scan electrodes of the capacitive touch sensor modifying the electric field which is radiated from the scan electrodes such that the self capacitance of the affected electrodes and mutual capacitance between affected electrodes is modified and detected by the electrode capacitive sensor circuitry. Heretofore, for contemporary capacitive touch screens which employ mutual capacitance technology to reliably detect passive devices it has been necessary for passive devices to have a tip geometry on the order of a human finger tip. Additionally, heretofore such devices are limited to being in contact with the capacitive touch screen to be detectable. In addition to passive devices, active devices which emit an electric or magnetic field have been postulated or developed which produce either a magnetic field or an electric field which is detected by the capacitive touch screen circuitry and enable a much smaller tip. Heretofore, active devices which rely on magnetic fields operate on the principle of inducing electric currents in the conductors in a capactive touch screen which are then detected by the capacitive touch screen circuitry. However, magnetic fields suffer from non-uniform directionality and therefore limited accuracy and may not be effective or compatible with all capacitive touch screens. In addition, active devices have been developed which rely on creating electric fields which are detected by the capacitive touch screen circuitry. However, heretofore, active electric field devices require a wire connection to the ground reference of the capacitive touch screen to establish a common reference. This results in a physically intrusive ground reference wire connecting the active electric field device to the capacitive touch screen circuitry.
It is an object of the present invention to provide a method to emulate touch events on a capacitive touch sensor. It is yet another object of the present invention to provide a method to emulate multiple touch events on a capacitive touch sensor array. It is yet another object of the present invention to provide a method to emulate single and multiple touch gestures on a capacitive touch sensor array.
It is an additional object of the present invention to provide a device which emulates touch events on a capacitive touch sensor, which has a means to monitor electric field emissions from scan electrodes of a capacitive touch sensor, and has a means to amplify the monitored electric field emissions and a means to capacitively couple the amplified electric field to the scan electrodes of the capacitive touch sensor emulating a touch event.
It is an additional object of the present invention to provide a method for emulating single-touch events on a capacitive touch sensor array consisting of the steps of monitoring the electric field emissions from scan electrodes in a region of the capacitive touch sensor array amplifying the monitored electric field emissions and coupling the amplified electric field to the capacitive touch sensor array scan electrodes inducing a voltage which emulates the presence of a touch event in the region.
It is an additional object of the present invention to provide a method for emulating touch events at a plurality of locations on a capacitive touch sensor array consisting of the steps of monitoring the electric field emissions from scan electrodes of the capacitive touch sensor array, predicting the electric field emissions at the plurality of touch locations of the capacitive touch sensor array from the monitored electric field emissions, synthesizing a plurality of electric fields which are coherent and proportional to the predicted electric field emissions and coupling the plurality of synthesized electric fields to the capacitive touch sensor array scan electrodes inducing voltages which emulate the presence of the touch events at the plurality of locations.
It is an additional object of the present invention to provide a method for emulating multiple-touch gesture movements on a capacitive touch sensor array consisting of the steps of monitoring the electric field emissions from scan electrodes of the capacitive touch sensor array, predicting the electric field emissions from electrodes at a plurality of locations spanning the gesture movement from the monitored electric field emissions, generating a sequence of emulated touch events at time varying-locations spanning the gesture movement by synthesizing electric fields which are coincident to the scan time of each electrode at the location of emulated touch event and is also coherent and phase aligned to the scan frequency of the electrode, and coupling the plurality of synthesized electric fields to the capacitive sensor array electrodes inducing voltages which emulate touch events such that the sequence of emulated touch events animates a gesture movement.
It is an additional object of the present invention to provide a device for emulating single-touch events on a capacitive touch sensor array which has a means to monitor the electric field emissions from a plurality of scan electrodes at a location of the capacitive touch sensor array, an electric field synthesizing means to synthesize an electric field that is coherent and proportional to the monitored electric field emissions and a coupling means to couple the synthesized electric field to the capacitive touch sensor array scan electrodes inducing voltages which emulate the presence of a touch event at the location.
It is an additional object of the present invention to provide a device for emulating touch events at a plurality of locations on a capacitive touch sensor array which includes a means to monitor the electric field emissions from scan electrodes of the capacitive touch sensor array, a predicting means to predict the electric field emissions at the plurality of touch locations of the capacitive touch sensor array from the monitored electric field emissions, a synthesizing means to synthesize a plurality of electric fields which are coherent and proportional to the predicted electric field emissions and a coupling means to couple the plurality of synthesized electric fields to the capacitive touch sensor array scan electrodes inducing voltages which emulate presence of the touch events at the plurality of locations.
It is an additional object of the present invention to provide a device for emulating multiple-touch gesture movements on a capacitive touch sensor array including a monitoring means to monitor the electric field emissions from scan electrodes of the capacitive touch sensor array, a predicting means to predict the electric field emissions from electrodes at a plurality of locations spanning the gesture movement from the monitored electric field emissions, a generating means to generate a sequence of emulated touch events at time varying-locations spanning the gesture movement by synthesizing electric fields which are coincident to the scan time of each electrode at the location of emulated touch event and is also coherent and phase aligned to the scan frequency of the electrode, and a coupling means to couple the plurality of synthesized electric fields to the capacitive sensor array electrodes inducing voltages which emulate touch events such that the sequence of emulated touch events animates a gesture movement.
It is yet a more specific object of the present invention to provide an active capacitance stylus device which emulates multi-touch finger gestures and has a fine tip.
It is a more specific object of the present invention to provide an apparatus which emulates multiple touch finger gestures on a capacitive touch screen.
It is yet another object of the present invention to provide a method to determine the angular orientation of a capacitive touch sensor array relative to a reference by monitoring the emitted electric fields from the scan electrodes of the capacitive touch sensor array.
It is yet another object of the present invention to provide a device to determine the orientation, horizontal and vertical position, direction of movement, velocity, and pressure of the apparatus on a capacitive touch sensor array by monitoring the electric fields emitted from the scan electrodes of the capacitive touch sensor array.
It is yet another object of the present invention to provide a device which produces electric and magnetic fields to emulate multi-touch finger gestures on a capacitive touch screen.
It is yet another object of the present invention to provide a device which modulates emulated touch events to enable communicating data to a capacitive touch sensor array.
It is yet another object of the present invention to provide a device which modulates emulated touch events to enable rejecting non emulated touch events to a capacitive touch sensor array.